I should clarify some assumptions that were made in this thread; for those that have never done electrical work in different parts of the world.

Unlike most of the world, in Canada/USA most homes are build from wood. (Stone/brick is used on the outside of the house for beauty only.  It adds no structural support.  In fact, we use metal ties every few rows of brick, to attach the stone/brick to the wood!)

Wood is cheap .. I mean REALLY REALLY cheap for us.  We have forests in Canada that are bigger than 3X the size of all of Europe.  It's also a lot faster/easier to work with wood, than with stone.  Wood is also a lot warmer (imagine walking on a concrete slab when it's -30C outside .. imagine how much it will cost you to heat a concrete house vs a wood house).

Between the wood studs/joists (typically set 16" apart) insulation is installed, and finally, drywall/gypsum board is screwed into the wood. Inside these cavities, electrical, plumbing, cable TV, etc is ran.  Holes are drilled into the wood, and wire is pulled.  Typical electrical wire is called 14/2 (14 gauge solid core with 2 wires insulated, and a 3rd not).  The 2 insulated wires are in plastic, and all 3 are then twisted and bunched together in another outer insulation of plastic.  black wire is 110V, white wire is neutral, uninsulated wire is ground (which is the same as neutral, as the 2 connect together in the electrical panel).

So metal "tubes" are NOT used.  I can imagine it to be very difficult to work with and not flexible.  The ends though have to go into metal boxes.  If there's ever a SPARK, you don't want it to start a fire and burn your house down!  Hence why metal boxes are required by law.  We have plastic boxes, but they can only be used for low voltage applications (telephone, cable TV, internet).

I live in a 100 year old house.  It had old electrical wire, and no cable TV.  The advantage of wood homes is that it's very easy to run new wire without breaking the wall.  You drill a small hole at the top and "fish" the wire through.  You can also use really long, flexible, drill bits that drill through the wood, and then you can pull the wire.  Little patching .. and you're done. 

Hope this clears some things up.  Please do continue to share stories.. construction methods interest me a lot .. I've never worked with a concrete house before, and always wondered how the heck electrical wire is pulled through one.

12,000$ is a lot of money.

In some parts of the world (like USA/Canada) the games you listed aren't worth more than 100-150$ each - in working condition.  But machines from Japan (like the small, white candy cabs) can sell for >1000$ each here (where in Japan, they can be picked up for ~100$)

I'm not sure how difficult/rare these games are where you found them.  Good luck and please post pictures.

Residential, you're right .. But all shopping centers, buildings, a lot of garages all have flat roofs.

Flat roofs are not popular for residential construction because it's considered cheap up front, but more expensive in the long run.  Replacing shingles on a gable roof is 50-75% cheaper than re-roofing a flat roof.  Also, in northern climates (where you can go down to -30C or colder) gable roofs make more sense, as you can put more insulation in your roof, and save a lot of $$$ on heating/cooling. Due to the more open space in the roof it also allows for better venting (removal of moist air that will typically rot your roof and cause mold to form in your home!)

Lastly, gable roofs have better drainage.  Most roofers don't do the best job in roofing a flat roof.  I've seen flat roofs that have standing water after rain.  The only way this water goes away is through evaporation (or eventually getting into your house!)

The trick for roofs to last for a long time (30+ years before needing to reroof) is to get the water away from the area as fast as possible.

It's good to see the big beams that will go the length of the lair, but where are they planning on using that pressure treated wood??  It's typically only used in spots that will be exposed to weather (i.e. decks) but not indoors (due to off gassing of nasty chemicals).

Here in Canada/USA bondo is a product mostly used in repairing cars after an accident.  It's actually a sort of hard plastic rather than wood which dries a hard pink color.  Is this the same product? (it's ready for dry/wet sanding after 1 hour or so)

Here in Canada they are as common as water.  Every home Reno store carries them.  They're also heavily used in the automotive industry.  Don't you have a local store which sells car parts for diyers?

Does it matter, the grill angle accuracy? you'll never see it!   

You guys are being a bit too rough.  It doesn't look that bad .. if it makes people want to also play the original, then why not?